Aquatic Sciences Meeting, Albuquerque 2001

SS40 Long-Term Research Programs in the Twenty-first Century (Spatial and Temporal Connections)

Date: Thursday, February 15, 2001, Time: 3:00:00 PM

Location: Ruidoso/Pecos

Cronin, T, M, US Geological Survey, Reston, USA, tcronin@usgs.gov

Willard, D, A, US Geological Survey, Reston, USA, dwillard@usgs.gov

CLIMATIC AND ANTHROPOGENIC INFLUENCE ON CHESAPEAKE BAY: IMPLICATIONS OF LONG-TERM TRENDS FOR MANAGEMENT AND RESTORATION

Many North American estuaries have been altered by human activities in their watersheds. However, instrumental records of water quality, biota, and physical parameters are too short either to separate human impacts from those of climatic and hydrological processes, or to determine "natural" pre-disturbance ecosystem conditions. Sedimentary, geochemical, and paleoecological records from mesohaline parts of Chesapeake Bay covering the last millennium show that the most severe human impacts were caused by 19th Century land clearance (increased turbidity and sedimentation) and 20th Century nutrient influx (greater seasonal hypoxia). However, paleo-records of both pre- and post-colonization (~1600-present) periods show that climate variability compounds and often overrides the effects of human activities, affecting turbidity and salinity (interannually and multi-decadally) and water temperature (decadally). Long-term patterns can be attributed directly to variability in regional precipitation and oceanic source-water temperature, but their temporal patterns suggest they may ultimately be related to broad climate anomalies associated with El Nino-Southern Oscillation and the North Atlantic Oscillation. If so, they have potential implications for improving ecosystem restoration and management efforts.

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Aquatic Sciences Meeting, Albuquerque 2001

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